Silly film. They could of stopped following that van at any time.
And the dialogue is laughable. Mel Gibson's character repeating what percentage a situation is likely to occur comes off as bad AI. I love Mel Gibson but he was phoning this one in.
I know the characters need money. But the film does not show us how desperate the two cops are. There is no need for them to get themselves in this situation. They even say multiple times they should just turn around.
They should of went with two lesser known actors and spent the money on other things.